Apple this week sent word to Washington state’s Attorney General that its new iOS 4.3 update for iPhone, iPad and iPod touch will require a password every time someone makes a purchase inside an app — closing a loophole that had resulted in some children unwittingly spending large sums to buy virtual items in games.

As documented in the past by the Associated Press and Washington Post, there was previously a 15-minute period after the download of an app in which a password wasn’t required for in-app purchases. In Capcom’s Smurfs’ Village game, some kids were buying “Smurfberries” for as much as $99.99 each during that 15-minute period.

In one case, an 8-year-old reportedly racked up a total bill of $1,400.

Paula Selis, senior counsel in the office of Washington AG Rob McKenna, cited that example in a Dec. 22 letter to Apple’s lawyers (PDF, 3 pages), pointing to similar problems with games such as “Tap Zoo” and “Bakery Story.”